Conventional heating, ventilation and air conditioning (HVAC) systems for vehicles generally include a housing, an evaporator, a heater core having a housing, an evaporator assembly coupled to the housing, an evaporator, a heater core, an air inlet, a fan and various doors or mode valves for controlling the volume and direction of air flow and generating outlet air of a desired volume and temperature. Together these components receive, temper and direct the flow of forced air through several outlets or vents in the vehicle. The outlets through which the forced air ultimately exits are determined by the various doors which move between open and closed positions and cause air flow to be forced in one direction or another or a combination of both. Air may be directed to various areas of the car depending on the state of the mode valves. For example, air may be forced through outlets directed at the windshield in a defrost or defog mode, or through outlets directed at mid-height level in an air-conditioning mode, or to lower outlets directed to the floor in a heat mode, or various combinations thereof. Although, air of any temperature may be directed to and through any of them.
More recently, designs utilizing a flexible film or fabric or cloth valve rather than doors have been proposed for controlling volume and direction of air flow. Generally, the flexible film valve is disposed in a frame having rollers. The flexible film valve includes various apertures formed therein, is rolled back and forth over a first roller to cover or uncover various openings and may include an actuator for controlling the roller to wind and unwind the film valve.